For Android App Name

Change the label name in your AndroidManifest.xml file:

 <application
    android:name="io.flutter.app.FlutterApplication"
    android:label="TheNameOfYourApp"   

For Package Name

Change the package name in your AndroidManifest.xml file:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="your.package.name">

Also in your build.gradle file inside app folder

defaultConfig {
    applicationId "your.package.name"
    minSdkVersion 16
    targetSdkVersion 27
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}

Finally, change the package in your MainActivity.java class

    package your.package.name;

    import android.os.Bundle;
    import io.flutter.app.FlutterActivity;
    import io.flutter.plugins.GeneratedPluginRegistrant;
    public class MainActivity extends FlutterActivity {

Change the directory name:

From:

  android\app\src\main\java\com\example\name

To:

  android\app\src\main\java\your\package\name

EDITED : 27-Dec-18

for package name just change in build build.gradle only

defaultConfig {
    applicationId "your.package.name"
    minSdkVersion 16
    targetSdkVersion 27
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}

For iOS

Change the bundle identifier from your Info.plist file inside your ios/Runner directory.

<key>CFBundleIdentifier</key>
<string>com.your.packagename</string>

UPDATE

To avoid renaming the package and bundle identifier, you can start your project using this command in your terminal:

flutter create --org com.yourdomain appname

Change name attribute in pubspec.yaml (line 1)

For the name of apk, change android:label in AndroidManifest.xml

Changing name manually doesn’t seem to work, throws gradle errors, well in my case it does throw error.

So I usually create a new flutter project.

I use below mentioned command to create a new flutter app

flutter create --org com.yourdomain appname

your project will have the package name as -> com.yourdomain.appname

if you just want to keep your package name as com.appname then make some changes as below

flutter create --org com appname

Android

In Android the package name is in the AndroidManifest:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    ...
    package="com.example.appname">

iOS

In iOS the package name is the bundle identifier in Info.plist:

<key>CFBundleIdentifier</key>
<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>

which is found in Runner.xcodeproj/project.pbxproj:

PRODUCT_BUNDLE_IDENTIFIER = com.example.appname;

Changing the name

The package name is found in more than one location, so to change the name you should search the whole project for occurrences of your old project name and change them all.

Android Studio and VS Code:

• Mac: Command + Shift + F
• Linux/Windows: Ctrl + Shift + F

Thanks to diegoveloper for help with iOS.

Update:

After coming back to this page a few different times, I’m thinking it’s just easier and cleaner to start a new project with the right name and then copy the old files over.

change in all AndroidManifest.xml files of your Flutter Project, –> package=”your.name.app”
(app/src/debug/AndroidManifest.xml) and
(app/src/main/AndroidManifest.xml) and (app/src/profile/AndroidManifest.xml)

good look !!

Updated You have to change the package name to your desired package name in these
five location.

1.) src/profile/AndroidManifest.xml
2.) src/debug/AndroidManifest.xml
3.) src/main/AdroidManifest.xml
4.) build.gradle .
       defaultConfig {
           applicationId
5.) MainActivity.java on "package"

last step is to run flutter clean

This is how i renamed package for both ios and android

1. Go to build.gradle in app module and rename applicationId "com.company.name"
2. Go to Manifest.xml in app/src/main and rename package="com.company.name" and android:label="App Name"
3. Go to Manifest.xml in app/src/debug and rename package="com.company.name"
4. Go to Manifest.xml in app/src/profile and rename package="com.company.name"
5. Go to app/src/main/kotlin/com/something/something/MainActivity.kt and rename package="com.company.name"
6. Go to app/src/main/kotlin/ and rename each directory so that the structure looks like app/src/main/kotlin/com/company/name/
7. Go to pubspec.yaml in your project and change name: something to name: name, example :- if package name is com.abc.xyz the name: xyz
8. Go to each dart file in lib folder and rename the imports to the modified name.
9. Open XCode and open the runner file and click on Runner in project explorer.
10. Go to General -> double click on Bundle Identifier -> rename it to com.company.name
11. Go to Info.plist click on Bundle name -> rename it to your App Name.
12. close everything -> go to your flutter project and run this command in terminal flutter clean

I had two manifest.xml file in my app section,so I needed to change package name in both

You can follow this official documentation by Google: https://developer.android.com/studio/build/application-id.html

Application ID should be changed in Build.gradle, while package name can be changed in AndroidManifest.xml.

However one should be careful changing package name.

Also while re uploading the app, one should be careful since it matches the application ID of previously uploaded app with new upload.

On Visual Studio code

Edit > Replace in Files

On Android studio

1. Right click on your project > Replace in path

2. Write your old package and new package > Replace all